utilize Pattern Tree to decide the policy to use and modify HTTP response headers according to that policy

This commit also enhances the build script so that preprocessor conditionals can now use operators '&&' and '||'.
The features being developed are not yet included in the actual Haketilo build.
Some of the new source files contain similar functionality to other ones already existing in the source tree. At some point the latter will be removed.

1 files changed, 37 insertions, 5 deletions

diff --git a/compute_scripts.awk b/compute_scripts.awk
index b778934..e17d12c 100755
--- a/compute_scripts.awk
+++ b/compute_scripts.awk
@@ -28,7 +28,12 @@ BEGIN {
     path_ext_re   = "(\\.[-_.a-zA-Z0-9]*)?"
     path_re       = "^" path_dir_re identifier_re path_ext_re "$"
 
-    directive_args_patterns["IF"]      = "^(NOT[[:space:]]+)?" identifier_re "$"
+    if_clause_re = "!?" identifier_re
+    if_AND_re    = "([[:space:]]+&&[[:space:]]+" if_clause_re ")*"
+    if_OR_re     = "([[:space:]]+[|][|][[:space:]]+" if_clause_re ")*"
+
+    directive_args_patterns["IF"]      = ("^" if_clause_re \
+					  "(" if_AND_re "|" if_OR_re ")$")
     directive_args_patterns["ENDIF"]   = "^$"
     directive_args_patterns["ELSE"]    = "^$"
     directive_args_patterns["ELIF"]    = "^(NOT[[:space:]]+)?" identifier_re "$"
@@ -215,8 +220,7 @@ function process_file(path, read_path, mode,
 
 	if (directive == "IF") {
 	    if (if_nesting_true == if_nesting) {
-		if ((last_token(directive_args) in defines) ==	\
-		    (directive_args ~ /^[^[:space:]]+$/))
+		if (if_condition_true(directive_args))
 		    if_nesting_true++
 		else
 		    if_branch_processed = false
@@ -255,8 +259,7 @@ function process_file(path, read_path, mode,
 	    }
 
 	    if (if_nesting == if_nesting_true + 1 && !if_branch_processed &&
-		(last_token(directive_args) in defines) ==	\
-		(directive_args ~ /^[^[:space:]]+$/)) {
+		if_condition_true(directive_args)) {
 		if_nesting_true++
 	    } else if (if_nesting == if_nesting_true) {
 		if_branch_processed = true
@@ -323,6 +326,35 @@ function process_file(path, read_path, mode,
     delete reading[read_path]
 }
 
+function if_condition_true(directive_args,
+			   result, bool, first_iter, word, negated, alt) {
+    first_iter = true
+
+    while (directive_args) {
+	word = first_token(directive_args)
+	sub(/^[^[:space:]]+[[:space:]]*/, "", directive_args)
+	alt = alt || directive_args ~ /^[|][|]/
+	sub(/^[^[:space:]]+[[:space:]]*/, "", directive_args)
+
+	negated = word ~ /^!/
+	sub(/^!/, "", word)
+	bool = (word in defines) != negated
+
+	if (first_iter) {
+	    result = bool
+	    first_iter = false
+	    continue
+	}
+
+	if (alt)
+	    result = result || bool
+	else # if (directive_args ~ /^AND/)
+	    result = result && bool
+    }
+
+    return result
+}
+
 function include_file(root_path, read_path, included_path, line, verbatim,
 		      read_line, result) {
     if (validate_path(read_path, included_path, line))